Four-Valve High Pressure Pump

ABSTRACT

A four-valve high pressure pump having a drive and a pump part with a piston capable of moving in a cylinder. Two cylinder blocks are arranged on the ends of the cylinder, through which blocks a transition duct runs. The inlet for the medium to be pumped is provided on an inlet casing part. A medium duct communicating with the inlet extends through the inlet casing part, in which duct a non-return valve is arranged either side of the opening for the inlet and which communicates at each opposing end with a transition duct of a cylinder block. An outlet casing part is constructed in a similar fashion, with an outlet for the medium instead of the inlet. The inlet casing part and/or the outlet casing part is detachably fastened laterally on the cylinder blocks at the side in such a manner that it can be removed without further dismantling the pump part.

The invention relates to a four-valve high pressure pump having

-   a) a drive; -   b) a pump part which in turn comprises:     -   ba) a cylinder;     -   bb) two cylinder blocks which are arranged on the end faces of         the cylinder and through which a respective transition channel         extends, which opens at opposing ends into an outer surface of         the cylinder block and communicates in the central region with         the interior of the cylinder; -   c) an inlet housing part, which has     -   ca) an inlet for the medium to be pumped;     -   cb) a media channel which communicates with the inlet and in         which a respective non-return valve is arranged on both sides of         the opening point of the inlet and which communicates at its         opposing ends with a respective transition channel of a cylinder         block; -   d) an outlet housing part, which has:     -   da) an outlet for the medium to be pumped;     -   db) a media channel which communicates with the outlet and in         which a respective non-return valve is arranged on both sides of         the opening point of the outlet and which communicates at its         opposing ends with a respective transition channel of a cylinder         block; -   e) a piston which is movable back and forth in the cylinder and is     in driving communication with the drive.

High pressure pumps of this type are currently extensively used in the application of media, particularly in the motor industry. They are therefore used, for example, to apply PVC material as an underbody sealant or wax for body cavity protection. Adhesives are also processed with pumps of this type. However, four-valve high pressure pumps are essentially also suitable for liquids and are of course suitable for areas of use other than the application of materials and also outside the motor industry.

In known four-valve high pressure pumps of the type mentioned at the outset, the two cylinder blocks cover both the inlet housing part and the outlet housing part in the radial direction—in relation to the axis of the cylinder. The different parts are braced together by means of tie rods which pass axially parallel through the cylinder blocks.

However, this design has several disadvantages. The pump which is designed in this way is very heavy, which complicates its handling and particularly its transportation. Moreover, for maintenance of the different valves contained in the inlet housing part and the outlet housing part, the pump has to be substantially dismantled, which is very time-consuming.

The object of the present invention is to construct a four-valve high pressure pump of the type mentioned at the outset in such a way that it is more readily transportable and the valves are easier to maintain.

This object is achieved according to the invention in that,

-   f) the inlet housing part and/or the outlet housing part is     releasably fastened laterally on the cylinder blocks in such a way     that it can be removed without further dismantling the pump part.

According to the invention, it is recognised that the bracing of is the cylinder blocks, the inlet housing part and the outlet housing part, which is effected in the axial direction, results in the above-mentioned disadvantages. Therefore, the invention replaces this type of axial bracing by fastening the inlet housing part and/or the outlet housing part to the cylinder blocks from the side with the aid of special fastening means, for example with the aid of normal screws. The bracing of the different components takes place here in the radial direction—in relation to the axis of the cylinder. The cylinder blocks no longer cover the inlet housing part and/or the outlet housing in the radial direction. Therefore, the inlet housing part and/or the outlet housing part can be released from the other components of the pump part without difficulty, whether to thereby achieve a plurality of lighter parts for transportation or to gain access to the valves for maintenance purposes.

A particularly preferred embodiment of the invention is one in which the inlet housing part and/or the outlet housing part is pivotable about an axis extending perpendicularly to the axis of the cylinder after part of the fastening means has been released. In some cases, it is not necessary to fully remove the inlet housing part or the outlet housing part from the remaining pump part to gain access to the valves. It is sufficient to pivot it until it is possible to access the valves.

This access is facilitated in that exemplary embodiment of the invention in which the media channel of the inlet housing part and/or the media channel of the outlet housing part has at least one opening which reaches as far as an outer surface and can be closed by a plug. If the plug is removed, the non-return valves in the media channel can be reached by way of the relevant opening.

Exemplary embodiments of the invention are explained in more detail below with reference to the drawing, which shows:

FIG. 1 the side view of a first exemplary embodiment of a four-valve high pressure pump;

FIG. 2 a section through the pump part of the four-valve high pressure pump of FIG. 1, on an enlarged scale;

FIG. 3 a section according to line of FIG. 1;

FIG. 4 a section, similar to FIG. 3, through a second exemplary embodiment of a four-valve high pressure pump;

FIG. 5 a section, similar to FIGS. 3 and 4, through a third exemplary embodiment of a four-valve high pressure pump;

FIG. 6 a schematic view of the manner in which a valve unit can be dismantled from the pump part of the high pressure pump;

FIG. 7 a view, similar to FIG. 1, of a fourth exemplary embodiment of a four-valve high pressure pump;

FIG. 8 the four-valve high pressure pump of FIG. 7, seen in the direction of the arrow 350 therein;

FIG. 9 a view, similar to FIG. 8, but with the inlet housing part pivoted away;

FIG. 10 the four-valve high pressure pump of FIGS. 1 to 3 and 6 with the inlet housing part pivoted away.

Reference is firstly made to FIG. 1, in which the essential components of a four-valve high pressure pump are shown in a side view. This is denoted as a whole by the reference numeral 1. It comprises a drive 2, which can be of any design, operating for example electrically or pneumatically. The drive 2 is shown only partially and schematically. Of interest within the present context is the actual pump part 3, which is described in detail below. It is in communication with the drive 2 by way of four rod-like tie rods 4 (cf. FIG. 3) which are guided through the pump part 2 in a manner explained in more detail below and are fastened from below by means of nuts 5.

As revealed particularly in FIG. 2, the pump part 2 comprises a cylinder 9 whereof the interior is divided into a lower working chamber 7 and an upper working chamber 8 by a piston 6.

A solid cylinder block 10 and 11 is arranged in each case above and below the cylinder 9. The cylinder blocks 10, 11 are octagonal in plan view, as shown in FIG. 3; the tie rods 4 pass through them. Both cylinder blocks 10, 11 have a respective transition channel 12 and 13 which opens at opposing ends to opposing side faces (end faces) and, as a result of its angled form in the central region, into the respective adjacent working chamber 7 or 8 of the cylinder 9.

The piston 6 is seated on a piston rod 14 which is guided with a first portion 14 a through the transition channel 12 of the cylinder block 10 and upwardly out of this. This portion 14 a of the piston rod 14 is in communication with the starting element of the drive 2, as shown in FIG. 1.

A lower portion 14 b of the piston rod 14 is similarly guided downwards through the lower cylinder block 11 and moves with its lower end region in a piston rod guide 16, which is likewise shown in FIG. 1.

A respective valve unit 17 and 18 is screwed to opposing sides of the cylinder blocks 10, 11. Each valve unit 17, 18 has a housing part 20 and 21, through which a media channel 22 and 23 passes. The media channels 22, 23 extend in a vertical branch over virtually the entire vertical dimension of the housing parts 20, 21, but then bend at a right angle and thus lead into the side face of the housing parts 20, 21 so that they are each flush with the adjacent ends of the transition channels 12 and 13.

The valve unit 17 which is illustrated on the left in both

FIGS. 1 and 2 is constructed as an inlet valve unit. The housing part 20 associated therewith is therefore referred to below as “inlet housing part”. This has an inlet 24 to which the medium to be pumped is supplied at a certain charging pressure. The inlet 24 leads into the media channel 22, more precisely at a point between two spring-loaded non-return valves 25, 26.

The valve unit 18 which is illustrated on the right in FIGS. 1 and 2 serves as an outlet valve unit. The housing part 21 associated therewith is therefore referred to below as “outlet housing part”. To this end, this has an outlet 27 which starts from a point in the media channel 23 which is located between two spring-loaded non-return valves 28, 29.

The mode of operation of the pump part 2 corresponds entirely to that of the prior art and therefore does not need explaining in more detail.

FIG. 2 shows the pump part 2 during the downstroke of its piston 6. As a result of the pressure exerted by the piston 6, the inlet non-return valve 25 is closed here and the outlet non-return valve 29 is open. The pumped medium is pushed downwards out of the lower working chamber by the piston 6 and flows over the transition channel 13 into the media channel 23 and through the open non-return valve 29 to the discharge point 27.

As a result of the charging pressure of the medium supplied by way of the inlet 24 and as a result of the suction effect of the piston 6 during its downward movement, the upper inlet non-return valve 26 in FIG. 2 is open; the medium can flow out of the inlet 24 into the media channel 22, upwards from there through the non-return valve 26 into the transition channel 12 and finally into the upper working chamber 8 of the cylinder 9. The upper outlet non-return valve 28 in FIG. 2 is closed during this.

During the upstroke of the piston 6, the non-return valves 25, 26, 28, 29 alter their opening state. The medium supplied by way of the inlet 24 then flows downwards in the media channel 22 and into the first working chamber 7 of the cylinder 9 from below, whilst the medium located in the second working chamber 8 arrives from the upwardly shifting piston 6 at the outlet 27 by way of the outlet non-return valve 28.

The pump part 2 described is notable for the arrangement of the four valves 25, 26, 28, 29 in separate valve units fastened to the cylinder blocks 10, 11 from the outside. This design approach results in various advantages:

On the one hand, it is possible to remove the valve units 17, 18 from the central pump part for transportation. This then results in assemblies with a weight which is relatively easy to handle. It is therefore possible to achieve weights in the order of magnitude of 10 kg for the assemblies, particularly when aluminium is the material used.

An at least equally important advantage of the described construction lies in that it allows for easy maintenance of the different valves 25, 26, 28, 29. In the event of disturbances, for example in the event of blockages, the housing blocks 20, 21 of the valve units 17, 18 can be easily removed from the central part, as shown schematically in FIG. 6. In particular, the valves 25, 26, 28, 29 can then also be easily checked or, if required, replaced without the entire pump part 2 having to be dismantled.

In the exemplary embodiment described above, only one inlet 24 and only one outlet 27 was provided. However, constructions are also essentially conceivable in which a plurality of inlet and/or outlets are used. Two such examples are shown in FIGS. 4 and 5.

In FIG. 4, the pump part 103 has an inlet 124 and three outlets 127 a, 127 b, 127 c. This pump can be used for example so that the outlet 127 a serves as reserve whilst the outlets 127 b, 127 c lead to different consumers.

In the exemplary embodiment shown in FIG. 5, two inlets 224 a, 224 b and five outlets 227 a, 227 b, 227 c, 227 d, and 227 e are provided. Therefore, seven sides of the cylinder blocks 210, 211 are occupied. It would also be essentially possible for the eighth side of the cylinder blocks 210, 211 to be occupied by a further outlet or inlet. This is not the case in the exemplary embodiment shown in FIG. 5. The openings provided for this in the cylinder blocks 210, 211 are instead closed by a closure plate 230.

In many cases, to maintain the different valves in the pump part 3, it is not necessary to fully remove the housing parts 17, 18 containing these valves. It is sufficient to remove only three of the four fastening screws 19, as shown in FIG. 10 for the exemplary embodiment of FIG. 1. The corresponding housing part 17 or 18 can then be pivoted about the remaining screw 19 as a pivot axis. The plugs 31 which close the openings 30 of the media channels 22, 23 are then easily accessible and can be removed so that the valves 25, 26 and 28, 29 can be easily reached by way of the media channels 22, 23 for maintenance purposes.

FIGS. 7 to 9 show a modified exemplary embodiment in which the pivoting movement takes place in a somewhat different manner.

Here, a separate axis of rotation 333 is provided coaxially to the inlet 324 and the outlet 327. If the four fastening screws 319 are released, the corresponding housing part 317 and 318 can be pivoted about this axis of rotation 333 as shown in FIG. 9. The plugs leading to the media channels are again accessible and can be removed for maintenance purposes. 

1. A four-valve high pressure pump comprising: a) a drive; b) a pump part which in turn comprises: ba) a cylinder; bb) two cylinder blocks, which are arranged on the end faces of the cylinder and through which a respective transition channel extends, which opens at opposing ends into an outer surface of the cylinder block and communicates in the central region with the interior of the cylinder; c) an inlet housing part, which has ca) a media channel which communicates with the inlet and in which a respective non-return valve is arranged on both sides of the opening point of the inlet which and communicates at its opposing ends with a respective transition channel of a cylinder block; d) an outlet housing part, which has: da) an outlet for the medium to be pumped: db) a media channel which communicates with the outlet and in which a respective non-return valve is arranged on both sides of the opening point of the outlet and which communicates at its opposing ends with a respective transition channel of a cylinder block; e) a piston which is movable back and forth in the cylinder and is in driving communication with the drive; wherein f) the inlet housing part and/or the outlet housing part is releasably fastened laterally on the cylinder blocks in such a way that it can be removed without further dismantling the pump part.
 2. A four-valve high pressure pump according to claim 1, wherein the inlet housing part and/or the outlet housing part is pivotable about an axis extending perpendicularly to the axis of the cylinder after part of the fastening means has been released.
 3. A four-valve high pressure pump according to claim 1, wherein the media channel of the inlet housing part and/or the media channel of the outlet housing part has at least one opening which reaches as far as an outer surface and can be closed by a plug. 